future federal agents and police may have undetectable drones that can drive, fly, swim into nearly any environment. >> there may be as many as 30,000 unmanned vehicles in the air. >> professor nathan busch says designers are modeling the newest drones on nature. >> so mimicking the actions of insects, the way that they crawl, for example, or fly. >> reporter: they may be so small and agile the drones could access tight spaces, impossible for police to get to today. when the army was funding research into small robotic birds, we got a good look at each other. >> reporter: right now the hummingbird can only fly a little more than 10 minutes. at that size, imagine what it could do at ten hours. >> it could fly through small clearings, through trees and see inside. >> reporter: if one crashes or the camera fails, developers at the university of pennsylvania already have drones flying in siynchronized formations. in the hostage crises of the future, it could give them a swarm of available replacements. >> reporter: we know defense secretary leon panetta personally approved a request from the fbi to get